Reduced-pressure systems and methods employing a leak-detection member

ABSTRACT

Systems, methods, and apparatus are provided for detecting leaks in systems for treating a patient with reduced pressure. In one instance, a system includes a distribution manifold for disposing proximate to the tissue site and a sealing member for disposing over the distribution manifold and at least a portion of intact epidermis of the patient. The sealing member has at least a portion that is substantially transparent. The system further includes a reduced-pressure source associated with the distribution manifold for providing reduced pressure to the distribution manifold and a leak-detection member sized and configured to substantially surround the distribution manifold. The leak-detection member includes a detection material that develops a color contrast when a portion is exposed to air and a portion is not exposed to air. The leak detection member works with even low flow systems. Other systems, methods, and apparatus are presented.

RELATED APPLICATIONS

The present invention claims the benefit, under 35 USC §119(e), of thefiling of U.S. Provisional Patent Application Ser. No. 61/534,566,entitled “Reduced-Pressure Systems and Methods Employing aLeak-Detection Member,” by Locke et al., filed Sep. 14, 2011, which isincorporated herein by reference for all purposes.

BACKGROUND

The present disclosure relates generally to medical treatment systemsand, more particularly, but not by way of limitation, toreduced-pressure systems and methods employing a leak-detection member.

Clinical studies and practice have shown that providing a reducedpressure in proximity to a tissue site augments and accelerates thegrowth of new tissue at the tissue site The applications of thisphenomenon are numerous, but application of reduced pressure has beenparticularly successful in treating wounds. This treatment (frequentlyreferred to in the medical community as “negative pressure woundtherapy,” “reduced pressure therapy,” or “vacuum therapy”) provides anumber of benefits, which may include faster healing and increasedformulation of granulation tissue. Typically, reduced pressure isapplied to tissue through a porous pad or other manifold device. Theporous pad contains cells, pores, or pathways that are capable ofdistributing reduced pressure to the tissue and channeling fluids thatare drawn from the tissue. The porous pad is typically covered by adrape that forms a seal.

SUMMARY

According to an illustrative embodiment, a system for treating a tissuesite on a patient with reduced pressure includes a distribution manifoldfor disposing proximate to the tissue site and a sealing member fordisposing over the distribution manifold and at least a portion ofintact epidermis of the patient. The sealing member has at least aportion that is substantially transparent. The system further includes areduced-pressure source associated with the distribution manifold forproviding reduced pressure to the distribution manifold and aleak-detection member sized and configured to substantially surround thedistribution manifold. The leak-detection member includes a detectionmaterial that develops a color contrast when a portion of the detectionmaterial is exposed to air and a portion of the detection material isnot exposed to air.

According to another illustrative embodiment, a method for providingreduced-pressure treatment to a tissue site on a patient, the methodincludes disposing a distribution manifold proximate to the tissue siteand disposing a leak-detection member around the distribution manifold.The leak-detection member comprises a detection material that develops acolor contrast when a portion of the detection material is exposed toair and a portion is not exposed to air. The method further includescovering the distribution manifold and leak-detection member with asealing member. The sealing member has at least a portion that issubstantially transparent. The method also includes providing reducedpressure to the distribution manifold, identifying a first colorcontrast on the leak-detection member indicative of a first leak, andsealing the first leak.

According to another illustrative embodiment, a system for treating atissue site on a patient with reduced pressure includes a distributionmanifold for disposing proximate to the tissue site and a sealing memberfor disposing over the distribution manifold and at least a portion ofintact epidermis of the patient. The sealing member has at least aportion that is substantially transparent. The system further includes areduced-pressure source associated with the distribution manifold forproviding reduced pressure to the distribution manifold and aleak-detection member sized and configured to substantially surround thedistribution manifold. The leak-detection member comprises a detectionmaterial that develops a color contrast when a portion of the detectionmaterial is exposed to a challenge gas and a portion is not exposed tothe challenge gas. The system also includes a challenge gas distributorfor spraying challenge gas onto the sealing member.

According to another illustrative embodiment, a method for providingreduced pressure treatment to a tissue site on a patient includesdisposing a distribution manifold proximate to the tissue site anddisposing a leak-detection member around the distribution manifold. Theleak-detection comprises a detection material that develops a colorcontrast when a portion is exposed to a challenge gas and a portion isnot exposed to the challenge gas. The method further includes coveringthe distribution manifold and leak-detection member with a sealingmember. The sealing member has at least a portion that is substantiallytransparent. The method also includes providing reduced pressure to thedistribution manifold, spraying the challenge gas onto the sealingmember, identifying a first color contrast on the leak-detection memberindicative of a first leak, and sealing the first leak.

According to another illustrative embodiment, a system for treating atissue site on a patient with reduced pressure includes a distributionmanifold for disposing proximate to the tissue site and a sealing memberfor disposing over the distribution manifold and at least a portion ofintact epidermis of the patient. The sealing member has at least aportion that is substantially transparent. The system further includes areduced-pressure source associated with the distribution manifold forproviding reduced pressure to the distribution manifold and askin-preparation fluid comprising a detection material that develops acolor contrast when a portion of the detection material is exposed toair and a portion is not exposed to air.

According to another illustrative embodiment, a system for treating atissue site on a patient with reduced pressure includes a distributionmanifold for disposing proximate to the tissue site and a sealing memberfor disposing over the distribution manifold and at least a portion ofintact epidermis of the patient. The tissue-facing side of the sealingmember is covered at least partially with a first agent. The sealingmember has at least a portion that is substantially transparent. Thesystem further includes a reduced-pressure source associated with thedistribution manifold for providing reduced pressure to the distributionmanifold and a skin-preparation fluid comprising a second agent. Whenthe first agent of the sealing member and the second agent of theskin-preparation fluid combine, the two agents form a contact color thatis indicative of contact between the first agent and second agent.

According to another illustrative embodiment, a method for treating atissue site on a patient with reduced pressure includes the steps ofdisposing a distribution manifold adjacent to the tissue site andcovering the distribution manifold with a sealing member. The sealingmember has a first agent. The sealing member has at least a portion thatis substantially transparent. The method further includes disposing askin-preparation fluid onto epidermis proximate to and around the tissuesite The skin-preparation fluid has a second agent. The first agent ofthe sealing member and the second agent of the skin-preparation fluidcombine to form a contact color indicative of contact between the firstagent and second agent. The method also includes identifying anylocations on a peripheral portion of the sealing member lacking thecontact color and applying a force to the location on the peripheralportion of the sealing member that was lacking the contact color.

According to another illustrative embodiment, a method of manufacturinga system for treating a tissue site on a patient with reduced pressureincludes the steps of forming a distribution manifold for disposingproximate to the tissue site and forming a sealing member for disposingover the distribution manifold and at least a portion of intactepidermis of the patient. The sealing member has at least a portion thatis substantially transparent. The method further includes providing areduced-pressure source for fluidly coupling to the distributionmanifold and forming a leak-detection member sized and configured tosubstantially surround the distribution manifold. The leak-detectionmember comprises a detection material that develops a color contrastwhen a portion of the detection material is exposed to air and a portionis not exposed to air.

According to another illustrative embodiment, a system for treating atissue site on a patient with reduced pressure includes a distributionmanifold for disposing proximate to the tissue site and a sealing memberfor disposing over the distribution manifold and at least a portion ofintact epidermis of the patient. The sealing member has at least aportion that is substantially transparent. The sealing member comprisesa film that is at least partially covered on a tissue-facing side with ahydrophilic adhesive. The system further includes a reduced pressuresource associated with the distribution manifold for providing reducedpressure to the distribution manifold. Under reduced pressure, fluidexudate from the tissue site is brought into contact with thehydrophilic adhesive in locations where reduced pressure is acting andis not brought into contact with the hydrophilic adhesive in locationswhere reduced pressure is not acting. A color contrast is therebycreated.

According to another illustrative embodiment, a method for treating atissue site on a patient with reduced pressure includes the steps ofdisposing a distribution manifold proximate to the tissue site andcovering the distribution manifold and a portion of intact epidermis ofthe patient with a sealing member. The sealing member has at least aportion that is substantially transparent. The sealing member comprisesa film that is at least partially covered on a tissue-facing side with ahydrophilic adhesive. The method further includes fluidly coupling areduced-pressure source to the distribution manifold to provide reducedpressure to the distribution manifold whereby the reduced pressure movesexudate into contact with the hydrophilic adhesive in locations wherereduced pressure is acting and does not move exudate to locations wherereduced pressure is not acting. The method also includes identifyinglocations where exudate is not brought into contact with the hydrophilicadhesive as potential leak locations and sealing the potential leaklocations.

Other features and advantages of the illustrative embodiments willbecome apparent with reference to the drawings and detailed descriptionthat follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram, with a portion shown in cross section anda portion shown in perspective view, of an illustrative embodiment of asystem for treating a tissue site on a patient with reduced pressure;

FIG. 2 is a schematic, cross-section of an illustrative embodiment of asystem for treating a tissue site on a patient with reduced pressure;

FIG. 3A is a schematic, top plan view of a portion of the system of FIG.2;

FIG. 3B is the portion of a reduced-pressure system shown in FIG. 3Awith a leak shown;

FIG. 4 is a schematic, top plan view of an illustrative embodiment of asealing member and a leak-detection member; and

FIG. 5 is a schematic, top plan view of an illustrative embodiment of aportion of a system for treating a tissue site on a patient with reducedpressure.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following detailed description of the illustrative, non-limitingembodiments, reference is made to the accompanying drawings that form apart hereof. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it isunderstood that other embodiments may be utilized and that logicalstructural, mechanical, electrical, and chemical changes may be madewithout departing from the spirit or scope of the invention. To avoiddetail not necessary to enable those skilled in the art to practice theembodiments described herein, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of the illustrative embodiments are defined only by the appendedclaims.

Referring now to the drawings and initially and primarily to FIG. 1, asystem 100 for treating a tissue site 102 on a patient 104 with reducedpressure is presented that includes a leak-detection member 106. Thetissue site 102 may be, as a non-limiting example, an open wound 108involving a patient's epidermis 110, dermis 112, and possiblysubcutaneous tissue 114. In other examples, the tissue site 102 may be asurface wound on the patient's epidermis 110 or at another tissue siteThe tissue site 102 may be the bodily tissue of any human, animal, orother organism, including bone tissue, adipose tissue, muscle tissue,dermal tissue, vascular tissue, connective tissue, cartilage, tendons,ligaments, or any other tissue. Treatment of the tissue site 102 mayinclude the removal of fluids, e.g., exudate or ascites.

The system 100 includes a distribution manifold 116 for disposingproximate to the tissue site 102. The distribution manifold 116 has afirst side 118 and a second, tissue-facing side 120. The distributionmanifold 116 references a substance or structure that is provided toassist in applying reduced pressure to, delivering fluids to, orremoving fluids from the tissue site 102. The distribution manifold 116typically includes a plurality of flow channels or pathways thatdistribute fluids provided to and removed from the tissue site 102around the distribution manifold 116. In one illustrative embodiment,the flow channels or pathways are interconnected to improve distributionof fluids provided or removed from the tissue site 102. The distributionmanifold 116 may be a biocompatible material that is capable of beingplaced in contact with the tissue site 102 and distributing reducedpressure to the tissue site 102. Examples of the distribution manifold116 may include, without limitation, devices that have structuralelements arranged to form flow channels, such as, for example, cellularfoam, open-cell foam, porous tissue collections, liquids, gels, andfoams that include, or cure to include, flow channels. The distributionmanifold 116 may be porous and may be made from foam, gauze, felted mat,or any other material suited to a particular biological application. Inone embodiment, the distribution manifold 116 is a porous foam andincludes a plurality of interconnected cells or pores that act as flowchannels. The porous foam may be a polyurethane, open-cell, reticulatedfoam such as GranuFoam® material manufactured by Kinetic Concepts,Incorporated of San Antonio, Texas. In some situations, the distributionmanifold 116 may also be used to distribute fluids such as medications,antibacterials, growth factors, and various solutions to the tissue site102. Other layers may be included in or on the distribution manifold116, such as absorptive materials, wicking materials, hydrophobicmaterials, and hydrophilic materials.

In one illustrative embodiment, the distribution manifold 116 may beconstructed from bioresorbable materials that do not have to be removedfrom a patient's body following use of the system 100. Suitablebioresorbable materials may include, without limitation, a polymericblend of polylactic acid (PLA) and polyglycolic acid (PGA). Thepolymeric blend may also include without limitation polycarbonates,polyfumarates, and capralactones. The distribution manifold 116 mayfurther serve as a scaffold for new cell-growth, or a scaffold materialmay be used in conjunction with the distribution manifold 116 to promotecell-growth. A scaffold is a substance or structure used to enhance orpromote the growth of cells or formation of tissue, such as athree-dimensional porous structure that provides a template for cellgrowth. Illustrative examples of scaffold materials include calciumphosphate, collagen, PLA/PGA, coral hydroxy apatites, carbonates, orprocessed allograft materials.

The system 100 also includes a first or lower sealing member 122 fordisposing over the distribution manifold 116 and at least a portion ofthe intact epidermis 110 of the patient 104. The lower sealing member122 creates a sealed space 123 that contains the distribution manifold116. The lower sealing member 122 has a first side 124 and a second,tissue-facing side 126. The lower sealing member 122 has at least aportion that is substantially transparent so that colors and colorcontrasts on the leak-detection member 106 may be seen through the lowersealing member 122. The lower sealing member 122 is typically a drape,but the lower sealing member 122 may be any material that provides afluid seal under normal operating conditions. The lower sealing member122 may, for example, be an impermeable or semi-permeable, elastomericmaterial. As used herein, elastomeric means having the properties of anelastomer. Elastomeric generally refers to a polymeric material that hasrubber-like properties. More specifically, most elastomers have ultimateelongations greater than 100% and a significant amount of resilience.The resilience of a material refers to the material's ability to recoverfrom an elastic deformation. Examples of elastomers may include, but arenot limited to, natural rubbers, polyisoprene, styrene butadiene rubber,chloroprene rubber, polybutadiene, nitrile rubber, butyl rubber,ethylene propylene rubber, ethylene propylene diene monomer,chlorosulfonated polyethylene, polysulfide rubber, polyurethane (PU),EVA film, co-polyester, and silicones. Additional, specific examples ofsealing member materials include a silicone drape, a 3M Tegaderm® drape,or a polyurethane (PU) drape such as one available from Avery DennisonCorporation of Pasadena, Calif.

A first attachment device 128 may be used to hold the lower sealingmember 122 against the patient's epidermis 110 or another layer, such asa gasket or additional sealing member. The first attachment device 128may take numerous forms. For example, the first attachment device 128may be a medically acceptable, pressure-sensitive adhesive that extendsabout a periphery, a portion, or the entire lower sealing member 122. Asadditional examples, the attachment device 128 may be a double-sideddrape tape, paste, hydrocolloid, hydro gel or other sealing devices orelements. The first attachment device 128 may also be a sealing ring orother device. The first attachment device 128 is disposed on the second,tissue-facing side 126 of the lower sealing member 122. Before use, thefirst attachment device 128 may be covered by a release liner (notshown).

A liquid receptor 130 is fluidly coupled to the tissue site 102 forreceiving and, at least partially, retaining liquids. In theillustrative embodiment of FIG. 1, the liquid receptor 130 is formed byan absorbent layer 132 and may also include a first wicking layer 134and a second wicking layer 136. The wicking layers 134, 136 sandwich theabsorbent layer 132. The wicking layers 134, 136 are fluid permeable andattract liquids. The absorbent layer 132 may, as a non-limiting example,be a layer of super absorbent fibers. The absorbent layer 132 may befluidly coupled through apertures 138 to the lower sealing member 122,the first attachment device 128, and consequently to the tissue site102.

An upper sealing member 139 may be coupled with a second attachmentdevice 143 to a portion of the lower sealing member 122. Thus, the lowersealing member 122 and upper sealing member 139 may sandwich theabsorbent layer 132 and the wicking layers 134, 136. The upper sealingmember 139 may also be substantially transparent, at least at portions,so that contrasts on the leak-detection member 106 may be seen throughthe upper sealing member 139.

The system 100 also includes a reduced-pressure source 140 associatedwith the distribution manifold 116 for providing reduced pressure to thesealed space 123 and, in particular, to the distribution manifold 116.While the reduced-pressure source 140 may be any device for supplying areduced pressure, such as a vacuum pump, wall suction, micro-pump, orother source, in the illustrative embodiment of FIG. 1, thereduced-pressure source 140 is a micro-pump 142 that is adjacent to theliquid receptor 130. While the amount and nature of reduced pressureapplied to a tissue site will typically vary according to theapplication, the reduced pressure will typically be between −5 mm Hg and−500 mm Hg and more typically between −75 mm Hg and −300 mm Hg.

The micro-pump 142 may be a piezoelectric pump that may be sandwichedbetween two foam cushion layers 144, 146. The two foam cushion layers144, 146 may themselves be sandwiched between a lower ply 148 and anupper ply 150. The lower ply 148 and upper ply 150 may be bonded attheir peripheries. A first power unit 152 and a control unit 154 may bepositioned between the lower ply 148 and the upper ply 150 and may becoupled to the micro-pump 142 for powering and controlling themicro-pump 142. The micro-pump 142 may exhaust air through a pluralityof apertures 156 in the upper ply 150. A central aperture 158 mayfluidly couple a lower pressure side or suction side of the micro-pump142 to the second wicking layer 136. Reduced pressure may thereby bedelivered through the second wicking layer 136, absorbent layer 132, andapertures 138 to the sealed space 123 and ultimately to the tissue site102.

The system 100 also includes the leak-detection member 106. Theleak-detection member 106 allows a user to identify leaks of air orcertain gases from an exterior through a location where a substantiallygas tight seal has not been formed between the lower sealing member 122and the patient's epidermis 110. The leak-detection member 106 may besized and configured to substantially surround the distribution manifold116. The leak-detection member 106 surrounds at least where reducedpressure enters the sealed space 123. The leak-detection member 106 maycomprise a detection material that is reactive to air, including carbondioxide and oxygen to develop a color contrast when a portion is exposedto air and a portion is not exposed to air.

The leak-detection member 106 may be a curved member that is disposedaround (substantially 360 degrees about) the tissue site 102 beingtreated or around the distribution manifold 116. If air leaks betweenthe epidermis 110 and the lower sealing member 122, a color contrastwill develop on a portion of a leak path where the leak path encountersthe leak-detection member 106. The user may then visually identify theleak location since the leak location coincides with the color contrast.The user may then seal the leak. The leak may be sealed by rubbing onthe lower sealing member 122 to improve the seal or by adding additionalsealing members along an edge or periphery of the lower sealing member122 where the air first enters.

The leak-detection member 106 is formed from the detection material. Thedetection material may be an agent alone or combined with an adhesive.The agent may respond visually to the amount of oxygen (O₂), carbondioxide (CO₂), or other gas present. Thus, for example, if more oxygenor more carbon dioxide is present at one location on the leak-detectionmember 106 than at another location, as is the case with a leak in whichair enters, a visual indication will be established in the form of acolor contrast. The leak-detection member 106 may allow leaks with lowflow, e.g., as low as or less than 0.2 ml/hour, to be identified.

The leak-detection member 106 may substantially surround the tissue site102. Thus, when a leak occurs in any direction, the leak may beidentified. The leak-detection member 106 may be a single ring as shownin FIG. 1 or a plurality of rings or members or other shapes as shown inFIGS. 2, 3, and 4. The leak-detection member 106 may also be formed fromcurved segments that are spaced. The curved segments preferably cover360 degrees around the tissue site 102 so that a leak path in anydirection may be identified. In another illustrative embodiment, theleak-detection member 106 may be a region on the tissue-facing side 126of the lower sealing member 122 or may be concomitant with thetissue-facing side 126 of the lower sealing member 122 altogether.

In one illustrative embodiment, the detection material may be a materialthat changes color or reacts as the pH changes. Under normal atmosphericconditions, e.g., with normal levels of carbon dioxide, the pH of waterwill be about 5.7. (Carbon dioxide requires the presence of water toform a weak acid resulting in a pH drop; similarly, ammonia requiresmoisture to form a weak base). If carbon dioxide is used as a challengegas, which will be explained further below, the pH will be lower (3-4).In any event, the pH will increase when ammonia gas is detected and willdecrease when carbon dioxide is detected. The change in pH results in achange in the color. Thus, as the pH changes in a location but not inother locations, the color changes and creates a color contrast.Detection materials that respond as such to pH changes include thefollowing: litmus, bromocresol purple, bromocresol blue, azolitmin,methyl red, bromocresol green. The detection material may also be aREDOX-based dye that is sensitive to oxygen. Illustrative examples ofREDOX-based dyes that are sensitive to oxygen include the following:methylene Blue (available from Sigma), N-phenylanthranilic acid(available from Acros Organics), or Neutral Red (available from FisherScientific).

As another illustrative detection material, titanium dioxide andglycerol may be used. A mixture of titanium dioxide, methylene blue andglycerol becomes a colorimetric indicator for oxygen after activation byUV. The titanium dioxide oxidizes the glycerol (a sacrificial electrondonor), reduces the REDOX dye methylene blue to a colorless form until,on exposure to oxygen, the reduced methylene blue is oxidized back toits blue color.

In one illustrative embodiment, the detection material may be aultraviolet (UV) light sensitive ink. When exposed to UV, the inkbecomes colorless and sensitive to oxygen such that a blue color formsunder the influence of oxygen. Thus, the leak path will show a blue on aportion that is in contrast to the color on the non-leaking portions.The non-leaking portions starve the ink of oxygen and become colorless.Thus, the leak-detection member 106 may include such an ink and adetection tool, e.g., a UV light tool, may be activated to give off UVlight and help identify any leak paths.

In another illustrative example, the detection material is aphosphorescence material that becomes more fluorescent or lessfluorescent when exposed to air. Thus, a user may cause portions of theleak-detection member 106 to become fluorescent by exposing theleak-detection member 106 to a detection tool, e.g., UV light orInfrared light tool. If a leak exists, the gas in the air will cause thedetection material to be more or less fluorescent depending on thespecific material used.

In one illustrative embodiment, the detection material includes afluorescent agent that will fluoresce in response to UV light or IR andthat is disposed on the tissue-facing side 126 of the lower sealingmember 122. The detection material will fluoresce until the fluorescentagent contacts moisture and salt that are common on the epidermis 110.Upon coming into contact with the moisture and salt, the detectionmaterial will discontinue to fluoresce or not fluoresce with the samestrength (fluorescence quenching). In areas where no such contact ismade between the detection material and the epidermis 110, the detectionmaterial will continue to fluoresce. Thus, the user may observe a colorcontrast in locations where a leak is probably located, i.e., where thelower sealing member 122 is not contacting the epidermis 110.

In another illustrative embodiment, the leak-detection member 106includes a detection material that fluoresces under UV or IR even whenin contact with the epidermis 110. The detection material, however,experiences fluorescent quenching when exposed to oxygen. Thus, the leakpath will fluoresce less and will have a color contrast.

In another illustrative embodiment, the detection material is a materialthat responds to a challenge gas. A challenge gas is a gas presented onan outside of the sealing member. If a leak exists, the challenge gas ispulled into the leak path and reacts with the detection material. Forexample, after applying the system 100, the user may spray the challengegas using a challenge gas distributor. The challenge gas is typicallyheaver than air. The challenge gas is sprayed onto the sealing member,and if a leak exists, the challenge gas will enter the leak path andcause the detection material to take on a color contrast.

Continuing to refer primarily to FIG. 1, in operation, the user disposesthe distribution manifold 116 proximate to the tissue site 102 that isto be treated. The user then disposes the leak-detection member 106around the tissue site 102 or distribution manifold 116. The userdisposes the lower sealing member 122 over the distribution manifold 116and the leak-detection member 106. The leak-detection member 106 mayalready be attached to the second, tissue-facing side 126 of the lowersealing member 122 and may be applied as an aspect of disposing thelower sealing member 122 or may be disposed separately on the patient'sepidermis 110. In one illustrative embodiment, disposing theleak-detection member 106 may involve disposing a curved member formedfrom the detection material onto the epidermis 110 of the patient 104outboard of the tissue site 102. In another illustrative embodiment,disposing the leak-detection member 106 around the distribution manifold116 may involve applying a liquid that comprises the detection materialonto the intact epidermis 110 of the patient 104 outboard of the tissuesite 102.

Reduced pressure is then provided to the distribution manifold 116,e.g., by activating the micro-pump 142. After the system 100 operatesfor a period of time, if any leaks exist, air will be pulled into theleak path and the leak-detection member 106 will develop a colorcontrast as previously noted. The color contrast coincides with aportion of the leak path, and the user may use the visual cue to locatethe leak. The user may then seal the leak by applying force or rubbingthe leak path or by applying additional sealing members at an edge ofthe lower sealing member 122 proximate to the identified leak path.

Referring now primarily to FIG. 2, another illustrative embodiment ofthe system 100 for providing reduced pressure to the tissue site 102 onthe patient 104 is presented. The system is analogous in many respectsto the system 100 of FIG. 1. In this embodiment, however, thereduced-pressure source 140 is an external reduced-pressure source 141and the liquid receptor 130 is a canister or other external fluidreservoir 131.

The external reduced-pressure source 141 is fluidly coupled by areduced-pressure delivery conduit 162 to a reduced-pressure interface164. In one illustrative embodiment, the reduced-pressure interface 164is a T.R.A.C.® Pad or Sensa T.R.A.C.® Pad available from KCI of SanAntonio, Texas. The reduced-pressure interface 164 allows the reducedpressure to be delivered to the distribution manifold 116.

In this illustrative embodiment, only the lower or first sealing member122 is used and the leak-detection member 106 includes two concentricmembers. The concentric members forming the leak-detection member 106are shown best in FIGS. 3A-3B. Because in this illustrative embodimentthe lower sealing member 122 is transparent, the portions beneath (onthe tissue-facing side) of the lower sealing member 122 are shownwithout hidden lines. Other structural aspects of the system 100 of FIG.2 are analogous to FIG. 1 and are not further described.

Referring now primarily to FIG. 3A, a portion of the system of FIG. 2 ispresented in plan view. In FIG. 3A, either the system 100 has not beenactivated or has been activated but no leak has been detected. No leakis detected as shown by the absence of any color contrast on theleak-detection member 106. On the other hand, in FIG. 3B, a leak path166 is shown by color contrasts 168 on the leak-detection member 106.While generally not visible (other than the color contrasts 168), theleak path 166 is shown with broken lines beginning at an edge orperiphery 170 and extending to the distribution manifold 116 from wherethe leak flows into the reduced-pressure interface 164.

Application of the system 100 of FIGS. 2-3B is analogous to thatpresented for the system 100 of FIG. 1. It should be noted that in thevarious embodiments, the leak-detection member 106 may take many forms.The leak-detection member may be a single ring, a single member of anyshape, a plurality of concentric members such as concentric circlesshown in FIGS. 3A-3B or concentric squares shown in FIG. 4, a pluralityof spaced curved segments, or any other arrangement that will allow leakpaths in any direction to be detected.

Referring now primarily to FIG. 4, an illustrative embodiment of thelower sealing member 122 and leak-detection member 106 are presented. Inthis embodiment, the reduced-pressure source 140 has not yet beenapplied. Visual indicia 172 may be included on the lower sealing member122 to aid the user in centering the lower sealing member 122 on thetissue site.

Referring now primarily to FIG. 5, a portion of an illustrativeembodiment of a system 200 for treating a tissue site, e.g., tissue site102 in FIG. 1, on a patient with reduced pressure is presented. Thesystem 200 is analogous in many respects to the system of FIG. 1, andanalogous parts have been indicated by indexing the reference numeralsby 100. The system 200 includes a distribution manifold 216 fordisposing proximate to the tissue site. The system 200 also includes asealing member 222 for disposing over the distribution manifold 216 andat least a portion of intact epidermis of the patient. The sealingmember 222 has at least a portion that is substantially transparent toallow viewing of color contrasts. The sealing member 222 includes a filmthat is at least partially covered on a tissue-facing side with ahydrophilic adhesive 276. The hydrophilic adhesive 276 is preferably ina pattern that surrounds an entry point 278. The entry point 278 iswhere reduced pressure enters a sealed space formed by the sealingmember 222. The entry point 278 may be, for example, where areduced-pressure interface 264 is fluidly coupled to the sealed space.The sealed space is analogous to the sealed space 123 in FIGS. 1 and 2.In the illustrative embodiment of FIG. 5, the pattern of the hydrophilicadhesive 276 includes a first ring 280 relatively near the entry point278 and inboard of the peripheral edge of the distribution manifold 216and a second ring 282 outboard of the distribution manifold 216.

The system 200 includes a reduced-pressure source that is not explicitlyshown but is analogous to the external reduced-pressure source 141 ofFIG. 2. The reduced pressure source 141 is associated with thedistribution manifold 216 for providing reduced pressure to thedistribution manifold 216. Under the influence of reduced pressure,fluid exudate from the tissue site is brought into contact with thehydrophilic adhesive 276 at locations where reduced pressure is actingand is not brought into contact with the hydrophilic adhesive 276 atlocations where reduced pressure is not acting. Thus, where a leak path266 appears, the reduced pressure will be dissipated and the exudatewill not be brought into contact with the hydrophilic adhesive 276.Because the exudate has a color or tint, the locations on the patternedhydrophilic adhesive 276 where the leak exists will present a colorcontrast 268. As with the previous embodiments, the color contrast 268shows the location of the leak path and the leak may be sealed.

Referring again to FIGS. 1-4, according to an illustrative non-limitingembodiment, the leak-detection member 106 may be a skin-preparationfluid or included as an aspect of a skin-preparation fluid. Theskin-preparation fluid includes a detection material that develops acolor contrast when a portion is exposed to air and a portion is notexposed to air. The skin-preparation fluid is applied at least aroundthe tissue site. The tissue site is surrounded by the skin-preparationfluid. As a non-limiting example of the skin-preparation fluid, inaddition to skin preparation liquids, a REDOX color dye or other dye maybe included. The lower sealing member 122 is then applied as previouslydescribed. If a leak exists, the air contacting the detection materialin the skin-preparation fluid will create a color contrast in theskin-preparation fluid and thereby indicate the location of the leak. Inanother illustrative embodiment, the skin-preparation fluid includesmethylene blue that is applied. After applying other aspects of thesystem 100, the reduced pressure is applied and the portions of theskin-preparation fluid under the lower sealing member 122 with asubstantially air tight seal become starved for oxygen and change colorsto become clear. Any portions with a leak will, because of the air flow,remain blue and thereby indicate the leak location.

According to another illustrative embodiment, the system 100 fortreating the tissue site 102 on the patient 104 with reduced pressureincludes the distribution manifold 116 for disposing proximate to thetissue site 102 and the lower sealing member 122 for disposing over thedistribution manifold 116 and at least a portion of the intact epidermis110 of the patient 104. The tissue-facing side 126 of the lower sealingmember 122 is covered at least partially with a first agent. The lowersealing member 122 has at least a portion that is substantiallytransparent to allow viewing of color contrasts. The system 100 alsoincludes the reduced-pressure source 140 associated with thedistribution manifold 116 for providing reduced pressure to thedistribution manifold 116 and a skin-preparation fluid.

The skin-preparation fluid includes a second agent. When the first agentof the sealing member and the second agent of the skin-preparation fluidcombine, they form a contact color indicative of contact between thefirst agent and second agent. In places where they do not contact, thecolor does not change. Thus, in use, the user will be able to see acolor contrast at places where the lower sealing member 122 and theskin-preparation fluid on the patient's epidermis 110 are not touching.Such locations are probable leak locations and may be sealed by applyingforce, e.g., rubbing the probable leak location, or applying additionalsealing members at an edge near the probable leak location.

Although the present invention and its advantages have been disclosed inthe context of certain illustrative embodiments, it should be understoodthat various changes, substitutions, permutations, and alterations canbe made without departing from the scope of the invention as defined bythe appended claims. It will be appreciated that any feature that isdescribed in connection to any one embodiment may also be applicable toany other embodiment.

It will be understood that the benefits and advantages described abovemay relate to one embodiment or may relate to several embodiments. Itwill further be understood that reference to “an” item refers to one ormore of those items.

The steps of the methods described herein may be carried out in anysuitable order, or simultaneously where appropriate.

Where appropriate, aspects of any of the embodiments described above maybe combined with aspects of any of the other embodiments described toform further examples having comparable or different properties andaddressing the same or different problems.

It will be understood that the above description of preferredembodiments is given by way of example only and that variousmodifications may be made by those skilled in the art. The abovespecification, examples and data provide a complete description of thestructure and use of exemplary embodiments of the invention. Althoughvarious embodiments of the invention have been described above with acertain degree of particularity, or with reference to one or moreindividual embodiments, those skilled in the art could make numerousalterations to the disclosed embodiments without departing from thescope of the claims.

We claim:
 1. A system for treating a tissue site on a patient withreduced pressure, the system comprising: a distribution manifold fordisposing proximate to the tissue site; a sealing member for disposingover the distribution manifold, wherein the sealing member comprises atleast a portion that is substantially transparent, the sealing memberconfigured to form a sealed space having the distribution manifoldtherein; a reduced-pressure source associated with the distributionmanifold for providing reduced pressure to the distribution manifold;and a leak detection ring having an inner and outer circumference, theinner circumference configured to be disposed outboard of thedistribution manifold, the leak detection ring being formed from adetection material configured to develop a color contrast in response toa leak of the sealing member, the detection material being reactive toair and becoming fluorescent when exposed to a diction tool in anactivated state and changing fluorescence when exposed to oxygen.
 2. Thesystem of claim 1, wherein the leak detection ring comprises one or moremembers concentric with the distribution manifold.
 3. The system ofclaim 1, wherein the detection material further comprises a hydrophilicadhesive disposed in the leak detection ring on a tissue facing side ofthe sealing member.
 4. A system for treating a tissue site on a patientwith reduced pressure, the system comprising: a distribution manifoldfor disposing proximate to the tissue site; a sealing member fordisposing over the distribution manifold, wherein the sealing membercomprises at least a portion that is substantially transparent, thesealing member configured to form a sealed space having the distributionmanifold therein; a reduced-pressure source associated with thedistribution manifold for providing reduced pressure to the distributionmanifold; a leak detection ring having an inner and outer circumference,the inner circumference configured to be disposed outboard of thedistribution manifold, the leak detection ring being formed from adetection material configured to develop a color contrast in response toa leak of the sealing member; and wherein the detection materialcomprises a first agent covering at least a portion of a tissue-facingside of the sealing member, and a skin-preparation fluid forming theleak detection ring and having a second agent, the first agent of thesealing member and the second agent of the skin-preparation fluidforming a contact color when combined that is indicative of contactbetween the first agent and the second agent, the contact colorproviding the color contrast with portions of the first agent not incontact with the second agent.
 5. The system of claim 1, wherein thedetection material is selected from at least one of the following:methylene blue, N-phenylanthranilic acid, titanium dioxide, andglycerol.
 6. A method for providing reduced-pressure treatment to atissue site on a patient, the method comprising: disposing adistribution manifold proximate to the tissue site; disposing at leastone ring having an inner and outer circumference formed from a detectionmaterial around the distribution manifold and the tissue site onto atleast one of an epidermis of the patient outboard of the tissue site andonto a tissue-facing side of a sealing member, so that the innercircumference is outboard of the distribution manifold, the at least onering comprising one or more curved members; covering the distributionmanifold and at least partially covering the at least one ring with thesealing member to seal the distribution manifold in a sealed space,wherein the sealing member has at least a portion that is substantiallytransparent; providing reduced pressure to the distribution manifold;and identifying a color contrast in the detection material indicative ofa leak in the sealed space.
 7. A method for providing reduced-pressuretreatment to a tissue site on a patient, the method comprising:disposing a distribution manifold proximate to the tissue site;disposing at least one ring having an inner and outer circumferenceformed from a detection material around the distribution manifold andthe tissue, so that the inner circumference is outboard of thedistribution manifold by applying a liquid onto an intact epidermis ofthe patient outboard of the tissue site; covering the distributionmanifold and at least partially covering the at least one ring with asealing member to seal the distribution manifold in a sealed space,wherein the sealing member has at least a portion that is substantiallytransparent; providing reduced pressure to the distribution manifold;and identifying a color contrast in the detection material indicative ofa leak in the sealed space.
 8. The method of claim 6, wherein thedetection material reacts to air.
 9. A method for providingreduced-pressure treatment to a tissue site on a patient, the methodcomprising: disposing a distribution manifold proximate to the tissuesite; disposing at least one ring having an inner and outercircumference formed from a detection material around the distributionmanifold and the tissue site, so that the inner circumference isoutboard of the distribution manifold; covering the distributionmanifold and at least partially covering the at least one ring with asealing member to seal the distribution manifold in a sealed space,wherein the sealing member has at least a portion that is substantiallytransparent; providing reduced pressure to the distribution manifold;identifying a color contrast in the detection material indicative of aleak in the sealed space by: exposing the detection material to adetection tool so that the detection material fluoresces; andidentifying areas of the detection material having differingfluorescence.
 10. A method for providing reduced-pressure treatment to atissue site on a patient, the method comprising: disposing adistribution manifold proximate to the tissue site; disposing at leastone ring having an inner and outer circumference formed from a detectionmaterial around the distribution manifold and the tissue site, so thatthe inner circumference is outboard of the distribution manifold whereinthe detection material reacts to a challenge gas; covering thedistribution manifold and at least partially covering the at least onering with a sealing member to seal the distribution manifold in a sealedspace, wherein the sealing member has at least a portion that issubstantially transparent; providing reduced pressure to thedistribution manifold; identifying a color contrast in the detectionmaterial indicative of a leak in the sealed space by spraying thechallenge gas onto the sealing member.
 11. A method for providingreduced-pressure treatment to a tissue site on a patient, the methodcomprising: disposing a distribution manifold proximate to the tissuesite; disposing at least one ring having an inner and outercircumference formed from a detection material around the distributionmanifold and the tissue site, so that the inner circumference isoutboard of the distribution manifold by disposing a first agent on atissue-facing side of a sealing member, and disposing a skin-preparationfluid having a second agent on an intact epidermis of the patient,wherein the first agent of the sealing member and the second agent ofthe skin-preparation fluid form a contact color when combined that isindicative of contact between the first agent and the second agent andsealing of the sealed space; covering the distribution manifold and atleast partially covering the at least one ring with the sealing memberto seal the distribution manifold in a sealed space, wherein the sealingmember has at least a portion that is substantially transparent;providing reduced pressure to the distribution manifold; identifying acolor contrast in the detection material indicative of a leak in thesealed space.
 12. The method of claim 6, wherein disposing the at leastone ring comprises applying a hydrophilic adhesive to a tissue-facingside of the sealing member.
 13. A system for treating a tissue site on apatient with reduced pressure, the system comprising: a distributionmanifold for disposing proximate to the tissue site; a sealing memberfor disposing over the distribution manifold, wherein the sealing membercomprises at least a portion that is substantially transparent, thesealing member configured to form a sealed space having the distributionmanifold therein; a reduced-pressure source associated with thedistribution manifold for providing reduced pressure to the distributionmanifold; and a leak detection ring having an inner and outercircumference, the inner circumference configured to be disposedoutboard of the distribution manifold, the leak detection ring beingformed from a detection material configured to develop a color contrastin response to a leak of the sealing member and the detection materialreacts to a challenge gas sprayed onto the sealing member by a challengegas distributor.
 14. The system of claim 13, wherein the challenge gasis carbon dioxide.
 15. A system for treating a tissue site on a patientwith reduced pressure, the system comprising: a distribution manifoldfor disposing proximate to the tissue site; a sealing member fordisposing over the distribution manifold, wherein the sealing membercomprises at least a portion that is substantially transparent, thesealing member configured to form a sealed space having the distributionmanifold therein; a reduced-pressure source associated with thedistribution manifold for providing reduced pressure to the distributionmanifold; and a leak detection ring having an inner and outercircumference, the inner circumference configured to be disposedoutboard of the distribution manifold, the leak detection ring beingformed from a detection material configured to develop a color contrastin response to a leak of the sealing member and wherein the detectionmaterial comprises a skin-preparation fluid reactive to air.
 16. Thesystem of claim 1, wherein the leak detection ring is configured to bedisposed between the sealing member and the tissue site.